Muscle involvement in sarcoidosis: a retrospective and followup studies.

Objective: Muscle involvement is a frequent histopathologic feature of sarcoidosis, but its clinical presentation has been rarely reported and its longterm outcome is unclear. We describe the features and outcome of 5 patients with muscle sarcoidosis.
Methods: A retrospective study from hospital charts over the period 1985-2001 in 2 academic rheumatology centers.
Results: Muscle involvement was identified in 5 patients (3 women, 2 men) aged 37 to 61 years, out of a cohort of 45 patients with sarcoidosis. No symptomatic muscle involvement was observed in the 20 patients with Lofgren syndrome of our series. Muscle involvement was the initial feature of the disease in 2 patients. Three patients had nodular type and the 2 others the myositic type. Chronic myopathy was not observed. Followup of patients with muscle disease ranged from 30 to 144 months (mean 72.6). Prednisone was used at a starting dose from about 0.33 to 1 mg/kg/day in all patients, then progressively tapered, and was associated with use of hydroxychloroquine (HCQ) in 2 cases. One poorly compliant patient was persistently prescribed 40 mg/day prednisone and HCQ by his general practitioner and was still complaining of diffuse myalgia at the last 30-month followup visit. One patient also receiving HCQ experienced cardiac and renal relapse, leading to transient increase in steroid dosage, but remained symptom-free 3 years after steroid discontinuation. Muscle relapses occurred in the 3 other patients. Muscle symptoms disappeared after readministration of corticosteroids or increase of prednisone dosage. The first patient was symptom-free without any treatment at the last followup visit. The second was still taking 10 mg/day 144 months after disease onset because of steroid-dependent myalgia. The last patient was asymptomatic with 10 mg/day prednisone at the last evaluation.
Conclusion: Symptomatic muscle involvement may be an initial feature of chronic, and usually the systemic form of, sarcoidosis. It responds to corticosteroid therapy, but relapse seems to be frequent.